There is a current trend to develop hybrid cars, in which often the front axle is driven by an internal combustion engine and the rear axle is driven by an electric motor. Driving can occur by means of either axle or by a combination of the two. The electric motor is powered by batteries in the car, which may be charged by the internal combustion engine or otherwise.
An electrically driven drive axle arrangement shall be as simple, light-weight and cheap as possible while providing the necessary power and lifespan. Its dimensions shall be as small as possible, and its number of parts shall be as low as possible.